1. Field of the Invention
The present invention relates to a thin-film deposition apparatus using a cathodic arc discharge, and more particularly, to a thin-film deposition apparatus using a cathodic arc discharge, which evaporates an arc vapor material from a target and guides the evaporated material to be deposited on a substrate.
2. Description of the Related Art
Generally, an arc coating method, which is a physical vapor deposition method of a vacuum coating method, is to coat a thin film such that a plasma duct is fixed at the front end of a target, and charged particles generated by an arc discharge, i.e., plasma, are transferred from the target to a substrate to be coated. The arc coating method is applied to manufacture of general cutting tools, molds and semiconductor devices. For such application, a thin-film deposition apparatus has been developed, which prevents macroparticles, i.e., a lump of neutral particles of a target material, which deteriorate the quality of the thin film generated by the arc coating method, from landing on the substrate.
Referring to FIG. 1, a conventional serial thin-film deposition apparatus using a cathodic arc discharge includes a target 5 from which arc vapor materials are generated, a plasma duct 8 provided in front of the target 5, and a cylindrical electromagnet 1 for guiding the arc vapor materials generated from the target 5 so that the arc vapor materials may be deposited on a substrate 6 facing the target 5.
Among the arc vapor materials, i.e., electrons, target ions, neutral particles, macroparticles and charged macroparticles, generated from the target 5, the charged particles such as the electrons, target ions or charged macroparticles migrate along a magnetic flux line 7 by the electromagnet 1 to then be deposited on the substrate 6. Parts of the macroparticles and the neutral particles are ionized by a high-density plasma (electrons and ions) at the center of the electromagnet 1 to then be deposited on the substrate 6, and the remaining parts thereof stick to the inner wall of the plasma duct 8.
However, in the aforementioned thin-film deposition apparatus, since the target 5 and the substrate 6 face each other, parts of non-ionized macroparticles may be deposited on the substrate 6, which deteriorates the quality of the thin film.
To solve this problem, a rectangular thin-film deposition apparatus has been proposed, in which a plasma duct is bent and a magnetic field is distributed along the plasma duct. Referring to FIG. 2, the rectangular thin-film deposition apparatus includes a target 33 from which arc vapor materials are generated, a trigger electrode 35 contacting the target 33 in a state where a negative voltage is applied to the target 33, a plasma duct 39 having a bend of approximately 90.degree., a first electromagnet 46 disposed at the outer portion of the plasma duct 39 where the target 33 is installed, a second electromagnet 48 disposed at the bend of the plasma duct 39, and a third electromagnet 50 wrapped around at the end portion of the plasma duct 39.
In a state in which a voltage is applied to the target 33, if the trigger electrode 35 contacts the target 33, an arc is instantaneously generated, and arc vapor materials are generated while the generated arc stays on the target 33 for a predetermined time.
If currents are applied to the first, second and third electromagnets 46, 48 and 50, as shown in FIG. 3, magnetic flux is generated, shown by flux lines 40 distributed along the plasma duct 39. Thus, among the arc vapor materials generated from the target 33 (FIG. 2), charged particles are deposited on a substrate (not shown) along the magnetic flux lines 40. Also, parts of the neutral particles and macroparticles ionized by the high-density plasma are deposited to the substrate along the magnetic flux lines 40. Non-ionized neutral particles and macroparticles cannot reach the substrate and stick to the plasma duct 39 and a baffle 52 disposed at the inside wall of the plasma duct 39. That is to say, while most of the macroparticles travels around the plasma duct 39, they stick to the inner wall of the plasma duct 39 and the baffle 52 to then be removed.
In the above-described rectangular thin-film deposition apparatus, the magnetic flux lines 40 extend outward from inside the plasma duct 39 at the bend of the plasma duct 39. Thus, some of the charged particles migrating along the magnetic flux lines 40 collide on the inner wall of the bend, and vanish, thereby deteriorating the deposition efficiency of the thin film.